import java.util.Scanner;

public class Example09 {
    public static void main(String[] args){
        int grade =75;
        Scanner scl =new Scanner(System.in);
        grade = scl.nextInt();
        if (grade>80) {
            //满足条件 grade>80
            System.out.println("该成绩的等级为优");
        }else if (grade>70) {
            //不满足条件grade>80
            System.out.println("该成绩的等级为良");
        }else if (grade>60) {
            System.out.println("该成绩的等级为中");
        }else {
            System.out.println("该成绩的等级为差");
        }
    }
}
